JPS63225773A - Check valve - Google Patents

Abstract

PURPOSE:To absorb and relieve counter pressure by placing a shock absorbing member in a hollow section formed by an outer tube and an inner tube provided with a check mechanism. CONSTITUTION:An inner tube 2 inserted into an outer tube 1 and secured thereto is incorporating a check mechanism 3, while a hollow section 4 is formed between inner and outer circumferential faces of both tubes, and a spring is placed as a shock absorbing member 5 in the hollow section. A piston ring 6 is mounted slidably as a movable member at the open end portion of the hollow section 4 with air-tightness being maintained so as to enable compression of the shock absorbing member 5. Since the movable member 6 slides to compress the shock absorbing member 5 even when the pressure of fluid in secondary piping increases or pressure wave is produced therein, interior volume of secondary piping increases to absorb and relieve abnormal pressure rise or pressure wave.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is intended to prevent abnormal pressure rises and pressure waves that occur in the secondary fluid sealed when a valve such as a water supply valve is closed on the downstream side of a check valve. This invention relates to a check valve designed to provide relief.

[Conventional technology and its problems]

For example, it is installed between the end faucet of a general household water pipe and the water meter to prevent contaminated water from flowing back into the main pipe due to water outages, etc., and to prevent the water meter from receiving water from the backflow. The use of check valves is increasing as a means to resolve various inconveniences, but in this case, when the terminal water faucet is closed, if the check valve is simply equipped with a normal check valve,
The pressure of the secondary fluid sealed between the water faucet and the check valve increases abnormally due to sunlight, freezing, etc., causing damage to the secondary piping, various devices connected to the piping, and even the check valve. Inconveniences such as damage to the valve itself or adverse effects were observed.

In addition, in recent years, single-lever water faucets and mixer faucets that can be opened and closed with a single touch have become widely used in households. It has been pointed out that the so-called water hammer phenomenon is likely to occur due to the operation, and that the pressure waves generated due to this phenomenon have an adverse effect on the above-mentioned check valve and various equipment in the downstream piping system, and there is an urgent need to solve this problem. This is what has been done.

Although a relatively large water hammer preventer developed for the purpose of alleviating the water hammer phenomenon that occurs in general fluid flow channels is already known, this device is immediately used to prevent water hammer from occurring in the above-mentioned water piping. Using it between the stop valve and the end faucet requires a large installation space, increases the length of the piping at the core, and also requires increased sealing performance and maintenance of the connecting members due to its installation. A variety of problems were found during this period.

In order to deal with this, the applicant has slidably incorporated a check mechanism (1 port) in the valve surface [a) as shown in FIG. By interposing a spring (c) with appropriate elasticity in the spring, the abnormal pressure increase mainly on the secondary side (downstream side) of the check mechanism is absorbed.
Although a valve structure has already been developed to reduce the pressure (see Utility Model Application No. 55-34036), the check valve with the above structure is effective in alleviating the excessive pressure rise of the secondary fluid due to temperature changes, etc. Even if they were effective to some extent, there still remained the problem that the pressure waves generated by the water hammer phenomenon could not be effectively reduced.

[Means for solving problems]

Therefore, as a result of intensive experiments and research, the inventor of the present invention has found that abnormal pressure rise and pressure waves can be effectively alleviated by making it possible to separately increase the volume of the pipe downstream of the check valve as necessary. This is what we have investigated. That is, in the check valve of the present invention, an inner cylinder provided with a check mechanism is inserted into an outer cylinder, a space is formed between the two cylinders, a buffer material is contained in the space, and the above-mentioned By compressing the cushioning material via a movable member, the above-mentioned problems can be solved at once.

[For production]

The present invention has a special effect of absorbing and alleviating back pressure by increasing the internal volume of the tube at any time in response to abnormal pressure increases and pressure waves of the sealed fluid that occur in the tube downstream of the check valve. It is something.

〔Example〕

Hereinafter, the structure will be described in more detail according to the embodiment shown in the drawings. In the drawings, 1 is an outer cylinder, 2 is an inner cylinder that is inserted into and fixed to the outer cylinder, and has a check mechanism 3, which will be described later. In addition to having a built-in part, a step part of a certain length is provided around the outer periphery on the same side,
A space 4 is formed between the inner and outer circumferential surfaces of the two cylinders, and a shock absorbing material 5, for example, a spring, is elastically loaded in the space.

A piston ring 6 as a movable member is slidably attached to the open end of the space 4 while maintaining airtightness, so that the cushioning material 5 can be compressed.

In the figure, 1'' indicates a bottom step provided as a ring at the inner bottom of the outer cylinder to obtain an inflow gap for the secondary fluid, and 7 indicates a valve holder.

Further, as the buffer material 5, instead of the upper spring, pressurized air or an inert gas such as N2 gas may be filled in with appropriate means.

In addition, the movable member may also include bellows 8 (see Fig. 3), diaphragm 9 (see Fig. 4), etc., but in this case, the movable member may be sealed inside the bellows or by the diaphragm. A spring or an inert gas at an appropriate pressure is filled in advance as a buffer material 5 in the space provided.

On the other hand, the structure of the non-return mechanism 3 incorporated in the inner cylinder 2 is not particularly limited as long as it has a conventionally known non-return function, and the figure shows an example thereof. , for example, has a valve seat 10a on the inner circumferential surface and a vane lOb on the back surface.
A support ring 10 is formed by forming a middle cylinder 10c through the support ring 10, and a recessed part 11a is provided on the back surface, and the valve pipe 11b is connected to the middle cylinder 10.
The valve body 11 is comprised of a valve body 11 which is slidably inserted into the valve body c, and a spring 12 which is resiliently loaded between a concave portion 11a of the valve body and a middle cylinder.

Therefore, although the check valve of the present invention is able to stop backflow caused by water outages, etc., as with conventional check valves of this type, Even if an abnormal pressure increase or pressure wave occurs in the fluid in the secondary pipe due to temperature change or water hammer phenomenon, the movable member slides in the direction of the arrow in response to this and compresses the buffer material 5 (second (see figure), the intratubular volume on the secondary side increases, making it possible to reliably absorb and alleviate abnormal pressure increases or pressure waves.

However, if the internal pressure on the secondary side decreases due to the opening of the terminal water tap, etc., the movable member will return to its original position due to the compressed buffer material 5, and will be ready for the next abnormal pressure increase, etc. They wait.

Above, we have described the case where the inner cylinder of the check valve of the present invention is fixed to the outer cylinder, but FIG. This shows another embodiment in which the outer cylinder 1 is provided with a guide part 1a on the primary side, and the inner cylinder 2 is slidable along the inner peripheral surface of the guide part 1a. While the interior was being installed, the open end of the space 4 between the inner and outer cylinders was airtightly closed with the outer flange 2° of the inner cylinder 2, and inert gas at a constant pressure was injected into the space as a buffer material 5. It is something.

Therefore, in the above embodiment, the abnormal pressure increase, pressure waves, etc. generated in the fluid in the secondary pipe are applied to the back surface of the insert 7, so that the inner cylinder 2 along with the insert 7 is Since it slides against the gas pressure, the internal volume of the tube on the downstream side of the check valve increases, and in particular, abnormal pressure rise can be absorbed more efficiently.

〔Effect of the invention〕

As described above, the check valve of the present invention effectively suppresses pressure waves that occur due to excessive pressure rise of the secondary fluid or water hammer phenomenon caused by temperature changes, rapid closing of end faucets, etc. In addition to absorbing and mitigating adverse effects not only on the check valve but also on various devices in the secondary piping system, it is possible to simply install a water hammer preventer etc. separately in the secondary piping system. In comparison, the entire system is extremely compact, requiring less installation space, and there is no need to worry about sealing performance due to increased piping length or increased number of connecting members.

Furthermore, since the check valve of the present invention does not have its cushioning material constantly in contact with fluid, there is no risk of water scale or rust forming, and the movable members can operate smoothly and have high durability. It has many excellent advantages, such as providing an insulating effect on the core and helping to prevent the valve body from becoming inoperable due to freezing.

[Brief explanation of drawings]

Fig. 1 is a front view showing the upper half of the check valve of the present invention in a state where the flow is conducted to the secondary side, and Fig. 2 is a reverse view of the check valve of the present invention in a state where abnormal pressure increase is applied. A sectional view of the upper half of the stop valve, FIGS. 3 and 4 are front views showing another embodiment of the movable member with the upper half of the reverse valve of the present invention partially cut away, and FIG. 5 is a front view of the movable member according to the present invention. FIG. 6 is a cross-sectional view of the upper half of another embodiment of the present invention in a state where the flow is returned to the secondary side, and FIG. 6 is a vertical cross-sectional view of the center of the conventional check valve. In addition, in the figure, 1...outer cylinder, 2...inner cylinder, 3...return mechanism, 4...vacuum, 5...buffer material, 6...piston ring, 7...・Intervention. that's all

Claims (1)

[Claims] 1. An inner cylinder 2 provided with a check mechanism 3 is inserted into an outer cylinder 1 to form a space 4 between the two cylinders, and a cushioning material 5 is contained within the space. Additionally, a check valve characterized in that the buffer material 5 is compressed by a movable member. 2. Claim 1 in which the movable member is the piston ring 6
Check valve as described in section. 3. The check valve according to claim 1, wherein the movable member is a bellows 8. 4. The check valve according to claim 1, wherein the movable member is a diaphragm 9. 5. The check valve according to claim 1, wherein the movable member is the inner cylinder 2. 6. The check valve according to claim 2 or 5, wherein the buffer material 5 is a spring. 7. The check valve according to any one of claims 2 to 5, wherein the buffer material 5 is an inert gas.